Dietary factors and gestational diabetes mellitus: An umbrella review

•Vitamin D supplement more than 601 IU/d, probiotics intake greater than 5 × 109 CFU, and myo-inositol supplement may reduce gestational diabetes mellitus risk.•Potato consumption with 80 g/d increments, cholesterol intake, and heme iron intake may increase gestational diabetes mellitus risk.•Although there is insufficient high-certainty evidence to determine the associations of 27 dietary factors with GDM risk, this umbrella review provides evidence-based information for women of childbearing age before or during pregnancy.